Browsing by Person "Tsang, Catherine"

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A short study exploring the effect of the glycaemic index of the diet on energy intake and salivary steroid hormones
(2019-01-24) Al-Dujaili, Emad A. S.; Ashmore, Sophie; Tsang, Catherine
The glycaemic index or load (GI or GL) is a concept for ranking carbohydrate-rich foods based on the postprandial blood glucose response compared with a reference food (glucose). Due to the limited research investigating the effect of the GI or GL of the diet on salivary steroidal hormones, this explorative short study was conducted. 12 female participants consumed a low GI and a high GI diet for three days each, followed by a washout period between each intervention. Saliva was collected at baseline, and following the low or high GI diets. Cortisol and testosterone concentrations were measured by enzyme-linked immuno-sorbent assay (ELISA). GI and GL were significantly different between the low and high GI diets ( < 0.001). There was a small but significant increase in salivary cortisol after the high GI diet (7.38 to 10.93 ng/mL, = 0.036). No effect was observed after the low GI diet. Higher levels of testosterone were produced after the low GI diet (83.7 to 125.9 pg/mL, = 0.002), and no effect was found after the high GI diet. The total intake of calories consumed on the low GI diet was significantly lower compared to the high GI diet ( = 0.019). A low GI diet was associated with a small but significant increase in salivary testosterone, while a high GI diet increased cortisol levels. Altering the GI of the diet may influence overall energy intake and the health and wellbeing of female volunteers.
The absorption, metabolism and excretion of flavan-3-ols and procyanidins following the ingestion of a grape seed extract by rats
(Cambridge University Press, 2007-03-08) Tsang, Catherine; Auger, Cyril; Mullen, William; Bornet, Aurélie; Rouanet, Jean-Max; Crozier, Alan; Teissedre, Pierre-Louis
Rats were fed a grape seed extract (GSE) containing (+)-catechin, (−)-epicatechin and dimers, trimers, tetramers and polymeric procyanidins. Liver, kidney, brain and gastrointestinal (GI) tract together with plasma, urine and faeces were collected over a 24 h period and their flavan-3-ol content was analysed by HPLC with tandem mass spectrometry and diode array detection. Small amounts of the GSE flavan-3-ols moved out of the stomach and into the duodenum/jejunum, and to a greater extent the ileum 1 h after ingestion, and into the caecum after 2 h with relatively small amounts being detected in the colon after 3 h. The GI tract contained the parent GSE flavan-3-ols and procyanidins with only trace amounts of metabolites and there were no indications that proanthocyanidins were depolymerised in the GI tract releasing monomeric flavan-3-ols. Plasma contained exclusively catechin glucuronides and methylated glucuronide metabolites which were also detected in the liver and kidneys. These metabolites were also present in urine together with sulphated metabolites and low amounts of the procyanidin dimers B1, B2, B3 and B4 as well as the trimer C2 and an unknown GSE trimer. The amounts of (+)-catechin and (−)-epicatechin metabolites excreted in urine relative to the quantity of the monomers ingested were 27 and 36 %, respectively, after 24 h. This is similar to the levels of urinary excretion reported to occur by other investigators after feeding (−)-epicatechin to rats and provides further, albeit indirect, evidence that the procyanidin oligomers in the GSE were not depolymerised to monomers to any extent after ingestion. No convincing analytical data were obtained for the presence of flavan-3-ol metabolites in the brain.
Anthocyanin-rich Potato Improves Cardiovascular Risk Factors in Healthy Human Adults
(2017) Tsang, Catherine; Almoosawi, S; Smail, Nacer Foudil; Al-Dujaili, Emad
Arterial stiffness is an emerging risk factor for cardiovascular disease (CVD), and dietary polyphenols, particularly anthocyanins, may play an important role in mediating vascular tone. The present single-blind randomised cross-over placebo controlled study investigated the effect of consumption of an anthocyanin-rich potato, Purple Majesty (PM) in 14 healthy male and female adults. Participants consumed 200 g of cooked PM containing 114 mg anthocyanins, or placebo (Osprey) with negligible anthocyanin content for 14 days, separated by a 1-week washout period. Non-invasive assessment of vascular tone (arterial stiffness) by pulse wave velocity (PWV) was determined in addition to systolic (SBP) and diastolic blood pressure (DBP), high density lipoproteins (HDL), low-density lipoproteins (LDL), triglycerides, glucose, insulin resistance (HOMA-IR) and c-reactive protein (CRP). Arterial stiffness was significantly reduced (p=0.001) following PM consumption. There were no significant changes with any other clinical parameter measured, and no changes were observed following placebo. PM contained higher levels of total phenolics, total anthocyanins and antioxidant capacity and daily consumption of PM over 14 days was well tolerated by participants. The findings from this study suggest improved vascular tone following daily consumption of PM and inclusion in the diet could provide a rich and valuable source of anthocyanins.
Antioxidant Rich Potato Improves Arterial Stiffness in Healthy Adults
(Springer, 2018-06-26) Tsang, Catherine; Smail, Nacer Foudil; McDougall, G. J. M.; Al-Dujaili, Emad
Arterial stiffness is an emerging risk factor for cardiovascular disease and dietary anthocyanins may be important in mediating vascular tone. The present study investigated the effect of consumption of an anthocyanin-rich potato, Purple Majesty on arterial stiffness measured as pulse wave velocity in 14 healthy male and female adults. Participants consumed 200 g/day of cooked purple potato containing 288 mg anthocyanins, or a white potato containing negligible anthocyanins for 14 days, separated by a 7-day washout period. Non-invasive assessment of vascular tone by pulse wave velocity was determined in addition to systolic and diastolic blood pressure, high-density lipoproteins, low-density lipoproteins, triglycerides, glucose, insulin and C-reactive protein. Pulse wave velocity was significantly reduced (p = 0.001) following Purple Majesty consumption for 14-days. There were no significant changes with any other clinical parameter measured, and no changes following white potato consumption. The findings from this short-term study indicate a potential effect of Purple Majesty consumption on arterial stiffness.
Bioavailability and Urinary Excretion of Phenolic-Derived Metabolites after Acute Consumption of Purple Majesty Potato in Humans
(E-Cronicon, 2015-03-18) Tsang, Catherine; Smail, Nacer F.; McDougall, Gordon J.; Almoosawi, Suzana; Al-Dujaili, Emad A. S.
A novel purple potato variety, Purple Majesty (PM) contains an abundance of phenolic compounds, especially anthocyanins. The aim of this study was to assess the bioavailability of phenolic compounds in plasma measured as total polyphenols and urinary excretion of phenolic-derived metabolites after acute consumption of cooked PM. Five healthy male subjects (27-60 years; mean BMI: 26.7 ± 4.1) participated in a bioavailability study. Blood and urine were sampled at baseline and following consumption of 400 g cooked PM at 1h, 2h, 4h and 24h. A peak plasma antioxidant capacity was reached 1-2 hours post-consumption (from 1044 ± 281 µmol/L Fe(II) at baseline and increased to 1257 ± 180 after 1 hour (p = 0.045) and 1112 ± 251 µmol/L Fe(II) after 2 hours (borderline significance of p = 0.06). Total phenols level in plasma was reached after 2 hours (from 342.4 ± 28.3 at baseline to 368.4 ± 25 mg/L GAE). Liquid chromatography mass spectrometric (LC-MS) analysis was used to track the levels of anthocyanin-like derivatives and metabolites in the urine of volunteers after intake of the cooked Purple Majesty potatoes. No anthocyanin derivatives were detected in urine by liquid chromatography mass spectrometry indicating levels were < 2 nM. The majority of peaks that increased after intake were putatively identified as sulphated phenolic metabolites. Phenolic glucuronides were identified but other peaks remain unidentified. Hippuric acid was identified as a major phenolic derivative. Hydroxy benzoic derivatives, characteristic of intake of anthocyanins, were not detected in urine, however metabolites expected from the B-ring of petunidin (i.e. methyl gallic acid) may have been obscured by other peaks. Some metabolites could have arisen through metabolism of chlorogenic acid, which is present at ~ equivalent amounts to anthocyanins in cooked PM. In conclusion, acute consumption of PM resulted in an increase in excretion of urinary phenolic-derived metabolites. Identifying these unknown phenolic derivatives warrants further investigation.
Can Part of the Health Damage Linked to Alcohol Misuse in Scotland be Attributable to the Type of Drink and its Low Price (by Permitting a Rapid Rate of Consumption)? A Point of View
(Oxford Journals, 2010) Gill, Jan; Tsang, Catherine; Black, Heather; Chick, Jonathan
This article considers two sets of data describing the extent of consumption of white spirit drinks by a sample of patients who abuse alcohol and the analysis of drink antioxidant content. We present a proposal for discussion that the rapid consumption of alcoholic drinks, low in protective antioxidant compounds, may potentially be more damaging to the body.
Challenge your borders: Nutrition and Health
(2019) Tsang, Catherine
Consumption of Pomegranate Juice Attenuates Exercise - Induced Oxidative Stress, Blood Pressure and Urinary Cortisol/Cortisone Ratio in Human Adults
(E-Cronicon, 2016-08-23) Al-Dujaili, Emad A. S.; Good, Gillian; Tsang, Catherine
Background: Oxidative stress is exacerbated in overweight and obese individuals after acute exercise compared with their nonobese counterparts. Antioxidants supplementation of the diet may be one intervention to reduce exercise-induced oxidative stress in this vulnerable population. The aim of this study was to investigate whether polyphenol-rich pomegranate juice attenuates postexercise oxidative stress and contributors to oxidative stress (glucocorticoids) and blood pressure in healthy overweight subjects. Methods: Males and females participated in a randomized placebo controlled parallel pilot-study (mean BMI: 26.7 ± 6.6 kg/m2 ). Two groups of (n = 12) participants received either pomegranate pure juice (500 mL/day containing total polyphenols of 1685 mg GAE/L) or placebo (water matched for total energy) and all participants completed two standardized 30 min treadmill tests (50% Wmax) at baseline and after one week of the intervention. Results: Exercise induced lipid peroxidation (MDA) was lower following pomegranate juice consumption compared with placebo (31.2 ± 10.6 to 26.5 ± 9.8 MDA µmole/day) after 1 week (P = 0.035). Urinary free cortisol was reduced from 179.4 ± 53.2 to 125.6 ± 43.5 nmole/24h which was significant (p = 0.042). In addition, there was a statistically significant increase in urinary free cortisone: from 112.2 ± 40.4 to 187.6 ± 90.2 nmole/24 h (p = 0.045), and a significant decrease in the urinary free cortisol/cortisone ratio (p=0.009) from 1.6 ± 1.1 to 0.67 ± 0.55 following one week of pomegranate juice intake. Pomegranate juice consumption was also found to decrease systolic blood pressure pre-exercise (136.7 ± 11.7 to 131.8 ± 8.8 mmHg (p = 0.007), and post-exercise from 158.8 ± 15.8 to 148.1 ± 12.3 mmHg (p < 0.01) and diastolic blood pressure (86.3 ± 10.6 to 82.5 ± 6.8 mmHg (p = 0.04) and 103.1 ±12.5 to 93.9 ± 11.5 mmHg (p = 0.001), pre and post exercise, respectively. Correlation results between the change in Cortisol/cortisone ratio with the effect on blood pressure showed a negative significant association post pomegranate juice intake (p = 0.028 for systolic and p = 0,008 for diastolic BP). There were no changes in lipid peroxidation or blood pressure following placebo treatment. Conclusions: These findings suggest that pomegranate juice consumption prior to an acute bout of moderate intensity exercise can alleviate blood pressure and exercise-induced stress in the overweight and obese population.
Differential effect of polyphenol-rich dark chocolate on glucoregulatory and cardiovascular risk factors on healthy overweight and obese subjects: a randomized clinical trial
(Royal Society of Chemistry, 2012-07) Almoosawi, Suzana; Tsang, Catherine; Ostertag, L. M.; Fyfe, Lorna; Al-Dujaili, Emad A. S.
The association between excess cortisol and various parameters of metabolic syndrome including hypertension, insulin resistance and dyslipidaemia is increasingly recognised. The present single-blind randomised placebo-controlled cross-over study compared the effect of polyphenol-rich dark chocolate (DC) on biomarkers of glucose metabolism, lipid profile, and blood pressure (BP) in females with BMI 25 kg m-2 (n = 21) and females with BMI < 25 kg m-2 (n = 21). Volunteers consumed 20 g of DC containing 500 mg polyphenols or a placebo DC with negligible polyphenol-content daily for 4 weeks, separated by a 2-week washout period. Systolic BP and diastolic BP decreased after 4 weeks of polyphenol-rich DC. Placebo raised fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and salivary cortisol, an effect that was significantly different from polyphenol-rich DC which had a negligible effect on fasting insulin, HOMA-IR and salivary cortisol. Females with BMI 25 kg m-2 responded less favourably to placebo than lean females and consequently had higher fasting insulin and HOMA-IR, in addition to a lower quantitative sensitivity check index (QUICKI) after ingestion of placebo compared to polyphenol-rich DC. No significant changes in lipid profile were observed. This study provides evidence for the metabolic benefits of consuming polyphenol-rich dark chocolate while demonstrating the possibility of adverse effects occurring with polyphenol-poor chocolate placebo.
Effect of a tomato-rich diet on markers of cardiovascular disease risk in moderately overweight, disease-free, middle-aged adults: a randomized controlled trial
(Elsevier, 2012-04-04) Thies, Frank; Masson, Lindsey F; Rudd, Amelia; Vaughan, Nicholas; Tsang, Catherine; Brittenden, Julie; Simpson, William G; Duthie, Susan; Horgan, Graham W; Duthie, Garry
Background: Cardiovascular disease (CVD) is a major cause of mortality in the United Kingdom. Epidemiologic studies suggest that consumption of tomato-based foods may lower CVD risk. Such potential benefits have been ascribed in part to high concentrations of lycopene in the tomatoes. However, these findings have not yet been validated by comprehensive intervention trials. Objective: The aim of this study was to conduct a single-blind, randomized controlled intervention trial with healthy middle-aged volunteers to assess whether the consumption of tomato-based foods affects recognized biomarkers of CVD risk. Design: After a 4-wk run-in period with a low-tomato diet, 225 volunteers (94 men and 131 women) aged 40–65 y were randomly assigned into 1 of 3 dietary intervention groups and asked to consume a control diet (low in tomato-based foods), a high-tomato-based diet, or a control diet supplemented with lycopene capsules (10 mg/d) for 12 wk. Blood samples were collected at baseline, at 6 wk, and after the intervention and were analyzed for carotenoid and lipid profiles and inflammatory markers. Blood pressure, weight, and arterial stiffness were also measured. Dietary intake was also determined during the intervention. Results: None of the systemic markers (inflammatory markers, markers of insulin resistance and sensitivity) changed significantly after the dietary intervention. Moreover, lipid concentrations and arterial stiffness were also unaffected by the interventions. Conclusion: These data indicate that a relatively high daily consumption of tomato-based products (equivalent to 32–50 mg lycopene/d) or lycopene supplements (10 mg/d) is ineffective at reducing conventional CVD risk markers in moderately overweight, healthy, middle-aged individuals. This trial was registered at isrctn.org as ISRCTN34203810.
Effect of cinnamon (Cinnamomum Zeylanicum) supplementation on serum C-reactive protein concentrations: A meta-analysis and systematic review
(Elsevier, 2018-12-07) Vallianou, Natalia; Tsang, Catherine; Taghizadeh, Mohsen; Davoodvandi, Amirhossein; Jafarnejad, Sadegh
Objective: The effect of cinnamon (Cinnamomum Zeylanicum) on serum C-reactive protein (CRP), an acute phase protein commonly used as a marker of inflammation, is uncertain. Therefore, the objective of the present study was to conduct a systematic review and meta-analysis of published randomised controlled trials (RCTs) of cinnamon to determine the effect on levels of serum CRP, relative to controls. Design: Studies were identified by a search of electronic databases including PubMed, Cochrane Library, Google Scholar and Scopus before August 2018. Combined and stratified analyses were used. Weighted mean differences (WMD) and its 95% confidence interval were estimated for net change in serum CRP by using random-effects model. The heterogeneity of meta-analysis was assessed by χ2 and I2 test. Results: Six studies were identified, and data from 285 participants were included. Pooled analysis showed significant reductions in serum CRP (WMD: −0.81 mg/L, 95% CI: −1.36 to −0.26, p = 0.004), with significant heterogeneity between selected studies. Improvements in sub-group analysis were observed when baseline CRP levels were greater than 3 mg/dL, and in trials of >12 weeks duration. Doses <1500 mg/day and ≥1500 mg/day were effective in lowering serum CRP (WMD: −0.56 mg/dL, 95% CI: −1.01 to -0.10, p = 0.02 and WMD: −2.13 mg/dL, 95% CI: −4.08 to −0.19, p = 0.03), respectively, with significantly reduced heterogeneity in trials with lower doses of cinnamon <1500 mg/day (test for heterogeneity: P = 0.22 and I2 = 33%). No changes were found in controls. Conclusion: Cinnamon supplementation improves levels of serum CRP, particularly in chronic conditions, where basal CRP levels are raised. Further well-designed studies are warranted to confirm or not the above-mentioned findings.
Effect of Cocoa on Glucocorticoids and Markers of Stress
(ISCHOM, 2020-12) Tsang, Catherine
The effect of green-coffee-bean extract rich in chlorogenic acid on antioxidant status of healthy human volunteers
(Cambridge University Press, 2010-01) Almoosawi, Suzana; Tsang, Catherine; Davidson, Isobel M; Fyfe, Lorna
Several studies have linked consumption of green-coffee-bean extract (GCBE) rich in chlorogenic acid (CGA) with reduced blood pressure(Reference Watanabe, Arai and Mitsui1–Reference Ochiai, Jokura and Suzuki3). It is hypothesised that increased antioxidant activity could be one of the underlying mechanisms by which GCBE reduces blood pressure. To test this hypothesis a GCBE preparation rich in CGA was assessed by three extraction methods for antioxidant activity. In vivo antioxidant activity was also determined in a group of healthy volunteers. The phenolic content of GCBE, as determined by the Folin-Ciocalteu method, varied greatly between the ethanolic acidified water (0.2% (v/v) formic acid) and acetonitrile extract (acetonitrile–water containing 0.2% (v/v) formic acid; 50:50, v/v): 123 (sd 0.23), 131 (sd 0.66) and 211 (sd 0.51) mg gallic acid equivalents (GAE)/g extract respectively. Similar findings were observed with the Fe3+-reducing ability of plasma (FRAP) assay, wherein the acetonitrile extract exhibited a stronger Fe3+-reducing ability than the ethanolic extract (0.067 mmol/g extract v. 0.048 mmol/g extract). The 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) radical-scavenging activity of the ethanolic extract of GCBE was 70.4% at 50 μm as compared with ascorbic acid (86.1% inhibition at 50 μm) and GAE (82.2% at 50 μm). To examine in vivo antioxidant properties of GCBE thirteen healthy volunteers (age 36 (sd 11) years, BMI 28 (sd 2.5) kg/m2) consumed 200 mg GCBE containing 90 mg CGA twice daily for 2 weeks. In vivo antioxidant activity was determined using the Folin-Ciocalteu method and FRAP. There was a significant correlation between urinary polyphenols excretion as determined by the Folin-Ciocalteu method and FRAP (0.664, P<0.0001). However no significant increase in urinary antioxidant activity was observed (total phenolics: 173.2 (sd 137.8) mg GAE/g creatinine v. 175.20 (sd 115.7) mg GAE/g creatinine, P>0.05; FRAP: 2.07 (sd 0.9) mmol Fe2+/g creatinine v. 1.56 (sd 0.7) mmol Fe2+/g creatinine, P>0.05). Systolic blood pressure decreased from 119 (sd 10.5) to 114 (sd 9.1) mmHg (P=0.05) following the 2-week treatment. In conclusion, green coffee bean extract has a high antioxidant activity. However, no changes in antioxidant activity are observed in urine. This finding is consistent with previous findings of poor antioxidant activity of hippuric acid, the main urinary metabolite of chlorogenic acid(Reference Olthof, Hollman and Buijsman4). Further research is required to identify the mechanism(s) of reduction in blood pressure. The antioxidant activity of plasma should also be determined.
Effect of N-Acetylcysteine on Positive and Negative Syndrome Scale associated with Schizophrenia: A Meta-Analysis
(Mashhad University of Medical Sciences, 2020-10) Ghaderi, Amir; Bussu, Anna; Tsang, Catherine; Jafarnejad, Sadegh
Background and objective: N-acetylcysteine (NAC), a precursor of L-cysteine with antioxidant, anti-inﬂammatory and neurotropic effects, is a promising agent in alleviating symptoms associated with schizophrenia. However, the role of NAC on parameters of Positive and Negative Syndrome Scale (PANSS) remain uncertain. This systematic review and meta-analysis explored the effect of NAC on parameters of PANSS in patients with chronic schizophrenia. Methods: We searchedPubmed/MEDLINE™, PsycNET™, PsycLIT™, Scopus™ and Google Scholar™ for studies on the effect of NAC on PANSS in patients with schizophrenia from inception to March 2019. We adopted medical and non-medical subjects headings (MeSH, non-MeSH) and several keywords, including “NAC”, “N-acetylcysteine”, “N-acetyl cysteine”, “Acetylcysteine”, “N-Acetyl-L-cysteine”, “schizophrenia”, “psychotic disorder”, “psychosis”, “schizoaffective” and “dementia praecox”. Results: We identified seven trials with274 patients meeting the inclusion criteria, with follow up between 8-52 weeks, and NAC supplementation between 1200-3600 mg/day. Significant improvements in PANSS were identified following NAC for total (SMD=-0.61, 95% CI = -0.91, -0.31 ; P<0.001), general (SMD = -0.58; 95% CI = -0.90, -0.26; P=0.0004); and negative (SMD = -0.56; 95% CI = -0.92, -0.21; P = 0.001) scores, respectively. No significant heterogeneity was found among studies. Significant reductions were observed following sub-group analysis in trials ≤ 24 weeks duration, with appreciable effect size for total (SMD= -0.83), general (SMD= -0.67) and negative (SMD=-1.09) scores. Conclusion: Supplementation of NAC was effective in alleviating PANSS symptoms associated with schizophrenia in trials ≤ 24 weeks duration. The use of NAC as an adjunct seems promising and further investigation is warranted to determine its precise role.
Effect of Polyphenol Supplementation on Memory Functioning in Overweight and Obese Adults: A Systematic Review and Meta-Analysis
(MDPI, 2024-02-06) Farag, Sara; Tsang, Catherine; Al-Dujaili, Emad A. S.; Murphy, Philip N.
Negative health consequences of obesity include impaired neuronal functioning and cell death, thus bringing the risk of impaired cognitive functioning. Antioxidant properties of polyphenols offer a possible intervention for overweight people, but evidence for their effectiveness in supporting cognitive functioning is mixed. This review examined evidence from randomized controlled trials concerning the effect of polyphenols on tasks requiring either immediate or delayed retrieval of learned information, respectively, thus controlling for differences in cognitive processes and related neural substrates supporting respective task demands. Searches of the PubMed/Medline, PsycInfo, and Scopus databases identified 24 relevant primary studies with N = 2336 participants having a BMI ≥ 25.0 kg/m2. The participants’ mean age for the 24 studies exceeded 60 years. Respective meta-analyses produced a significant summary effect for immediate retrieval but not for delayed retrieval. The present findings support a potential positive effect of chronic supplementation with polyphenols, most notably flavonoids, on immediate retrieval in participants aged over 60 years with obesity being a risk factor for cognitive impairment. We recommend further investigation of this potential positive effect in participants with such risk factors. Future research on all populations should report the phenolic content of the supplementation administered and be specific regarding the cognitive processes tested.
Effect of Polyphenol-Rich Dark Chocolate on Salivary Cortisol and Mood in Adults
(MDPI, 2019-05-29) Tsang, Catherine; Hodgson, Lindsay; Bussu, Anna; Farhat, Grace; Al-Dujaili, Emad
The aim of the present study was to investigate whether ingestion of polyphenol-rich dark chocolate improved salivary cortisol levels and subjective mood states in adults recruited from a health and social care setting. Twenty-six participants ingested 25 g/day of a high polyphenol dark chocolate (containing 500 mg of total flavonoids) or a similar amount of a control dark chocolate containing negligible flavonoids for four weeks. Twenty-four-hour salivary glucocorticoid levels (cortisol and cortisone) were measured by an enzyme-linked immunosorbent assay, and subjective mood was assessed using a validated Positive Affect and Negative Affect Schedule. Total daily cortisol, morning cortisol, and the cortisol/cortisone ratio were significantly reduced (p < 0.001) after ingestion of only the high polyphenol dark chocolate. There were no significant differences between groups for overall scores for positive affect and negative affect. No changes were observed after the control dark chocolate, or any other parameter measured. In conclusion, the findings from this small-scale study indicate lowering of salivary cortisol levels following polyphenol-rich dark chocolate in adults recruited from a health and social care setting. Such changes may be attributable to their ability to inhibit 11β-hydroxysteroid dehydrogenase type 1 activity and warrant further investigation.
Encapsulation of ascorbic acid promotes the reduction of Maillard reaction products in UHT milk
(Royal Society of Chemistry, 2016-05-17) Troise, Antonio Dario; Vitiello, Daniele; Tsang, Catherine; Fiore, Alberto
The presence of amino groups and carbonyls renders fortified milk with ascorbic acid particularly susceptible to the reduction of available lysine and to the formation of Maillard reaction products (MRPs), as Nε-(carboxyethyl)-L-lysine (CEL), Nε-(carboxymethyl)-L-lysine (CML), Amadori products (APs) and off-flavors. A novel approach was proposed to control the Maillard reaction (MR) in fortified milk: ascorbic acid was encapsulated in a lipid coating and the effects were tested after a lab scale UHT treatment. Encapsulation promoted a delayed release of ascorbic acid and a reduction in the formation of MRPs. Total lysine increased up to 45% in milk with encapsulated ascorbic acid, while reductions in CML, CEL and furosine ranged from 10% to 53% compared with control samples. The effects were also investigated towards the formation of amide-AGEs (advanced glycation end products) by high resolution mass spectrometry (HRMS) revealing that several mechanisms coincide with the MR in the presence of ascorbic acid.
Functional Foods and Lifestyle Approaches for Diabetes Prevention and Management
(MDPI, 2017-12-01) Alkhatib, Ahmad; Tsang, Catherine; Tiss, Ali; Bahorun, Theeshan; Arefanian, Hossein; Barake, Roula; Khadir, Abdelkrim; Tuomilehto, Jaakko
Functional foods contain biologically active ingredients associated with physiological health benefits for preventing and managing chronic diseases, such as type 2 diabetes mellitus (T2DM). A regular consumption of functional foods may be associated with enhanced anti-oxidant, anti-inflammatory, insulin sensitivity, and anti-cholesterol functions, which are considered integral to prevent and manage T2DM. Components of the Mediterranean diet (MD)—such as fruits, vegetables, oily fish, olive oil, and tree nuts—serve as a model for functional foods based on their natural contents of nutraceuticals, including polyphenols, terpenoids, flavonoids, alkaloids, sterols, pigments, and unsaturated fatty acids. Polyphenols within MD and polyphenol-rich herbs—such as coffee, green tea, black tea, and yerba maté—have shown clinically-meaningful benefits on metabolic and microvascular activities, cholesterol and fasting glucose lowering, and anti-inflammation and anti-oxidation in high-risk and T2DM patients. However, combining exercise with functional food consumption can trigger and augment several metabolic and cardiovascular protective benefits, but it is under-investigated in people with T2DM and bariatric surgery patients. Detecting functional food benefits can now rely on an “omics” biological profiling of individuals’ molecular, genetics, transcriptomics, proteomics, and metabolomics, but is under-investigated in multi-component interventions. A personalized approach for preventing and managing T2DM should consider biological and behavioral models, and embed nutrition education as part of lifestyle diabetes prevention studies. Functional foods may provide additional benefits in such an approach.
The influence of moderate red wine consumption on antioxidant status and indices of oxidative stress associated with CHD in healthy volunteers
(Cambridge University Press, 2007-03-08) Tsang, Catherine; Higgins, Siobhan; Duthie, Garry G.; Duthie, Susan J.; Howie, Moira; Mullen, William; Lean, Michael E. J.; Crozier, Alan
The effects of moderate red wine consumption on the antioxidant status and indices of lipid peroxidation and oxidative stress associated with CHD were investigated. A randomised, controlled study was performed with twenty free-living healthy volunteers. Subjects in the red wine group consumed 375 ml red wine daily for 2 weeks. We measured the total concentration of phenolics and analysed the individual phenolics in the wine and plasma by HPLC with tandem MS. The antioxidant capacity of plasma was measured with electron spin resonance spectroscopy while homocysteine and fasting plasma lipids were also determined. The production of conjugated dienes and thiobarbituric acid-reactive substances (TBARS) were measured in Cu-oxidised LDL. Plasma total phenolic concentrations increased significantly after 2 weeks of daily red wine consumption (P≤0·001) and trace levels of metabolites, mainly glucuronides and methyl glucuronides of (+)-catechin and (−)-epicatechin, were detected in the plasma of the red wine group. These flavan-3-ol metabolites were not detected in plasma from the control group. The maximum concentrations of conjugated dienes and TBARS in Cu-oxidised LDL were reduced (P≤0·05) and HDL cholesterol concentrations increased (P≤0·05) following red wine consumption. The findings from the present study provide some evidence for potential protective effects of moderate consumption of red wine in healthy volunteers.
Intake of polyphenol-rich pomegranate pure juice influences urinary glucocorticoids, blood pressure and homeostasis model assessment of insulin resistance in human volunteers
(2012-08) Tsang, Catherine; Smail, Nacer Foudil; Almoosawi, Suzana; Davidson, Isobel; Al-Dujaili, Emad A. S.
Pomegranate juice (PJ; also known as pomegreat pure juice) provides a rich and varied source of polyphenolic compounds that may offer cardioprotective, anti-atherogenic and antihypertensive effects. The aim of this study was to investigate the effect of PJ consumption on glucocorticoids levels, blood pressure (BP) and insulin resistance in volunteers at high CVD risk. Subjects (twelve males and sixteen females) participated in a randomised, placebo-controlled cross-over study (BMI: 2677 (sd 336) kg/m2; mean age: 504 (sd 61) years). Volunteers were assessed at baseline, and at weeks 2 and 4 for anthropometry, BP and pulse wave velocity. Cortisol and cortisone levels in urine and saliva were determined by specific ELISA methods, and the cortisol/cortisone ratio was calculated. Fasting blood samples were obtained to assess plasma lipids, glucose, insulin and insulin resistance (homeostasis model assessment of insulin resistance). Volunteers consumed 500 ml of PJ or 500 ml of a placebo drink containing a similar amount of energy. Cortisol urinary output was reduced but not significant. However, cortisol/cortisone ratios in urine (P = 0009) and saliva (P = 0024) were significantly decreased. Systolic BP decreased from 1364 (sd 63) to 1289 (sd 51) mmHg (P = 0034), and diastolic BP from 803 (sd 429) to 755 (sd 517) mmHg (P = 0031) after 4 weeks of fruit juice consumption. Pulse wave velocity decreased from 75 (sd 086) to 744 (sd 094) m/s (P = 0035). There was also a significant reduction in fasting plasma insulin from 936 (sd 58) to 753 (sd 412) mIU/l (P = 0025) and of homeostasis model assessment of insulin resistance (from 2216 (sd 143) to 182 (sd 112), P = 0028). No significant changes were seen in the placebo arm of the study. These results suggest that PJ consumption can alleviate key cardiovascular risk factors in overweight and obese subjects that might be due to a reduction in both systolic and diastolic BP, possibly through the inhibition of 11_-hydroxysteroid dehydrogenase type 1 enzyme activity as evidenced by the reduction in the cortisol/cortisone ratio. The reduction in insulin resistance might have therapeutic benefits for patients with non-insulin-dependent diabetes, obesity and the metabolic syndrome.